2 * linux/kernel/time/timekeeping.c
4 * Kernel timekeeping code and accessor functions
6 * This code was moved from linux/kernel/timer.c.
7 * Please see that file for copyright and history logs.
11 #include <linux/timekeeper_internal.h>
12 #include <linux/module.h>
13 #include <linux/interrupt.h>
14 #include <linux/percpu.h>
15 #include <linux/init.h>
17 #include <linux/sched.h>
18 #include <linux/syscore_ops.h>
19 #include <linux/clocksource.h>
20 #include <linux/jiffies.h>
21 #include <linux/time.h>
22 #include <linux/tick.h>
23 #include <linux/stop_machine.h>
24 #include <linux/pvclock_gtod.h>
26 #include "tick-internal.h"
27 #include "ntp_internal.h"
29 static struct timekeeper timekeeper
;
30 static DEFINE_RAW_SPINLOCK(timekeeper_lock
);
31 static seqcount_t timekeeper_seq
;
33 /* flag for if timekeeping is suspended */
34 int __read_mostly timekeeping_suspended
;
36 /* Flag for if there is a persistent clock on this platform */
37 bool __read_mostly persistent_clock_exist
= false;
39 static inline void tk_normalize_xtime(struct timekeeper
*tk
)
41 while (tk
->xtime_nsec
>= ((u64
)NSEC_PER_SEC
<< tk
->shift
)) {
42 tk
->xtime_nsec
-= (u64
)NSEC_PER_SEC
<< tk
->shift
;
47 static void tk_set_xtime(struct timekeeper
*tk
, const struct timespec
*ts
)
49 tk
->xtime_sec
= ts
->tv_sec
;
50 tk
->xtime_nsec
= (u64
)ts
->tv_nsec
<< tk
->shift
;
53 static void tk_xtime_add(struct timekeeper
*tk
, const struct timespec
*ts
)
55 tk
->xtime_sec
+= ts
->tv_sec
;
56 tk
->xtime_nsec
+= (u64
)ts
->tv_nsec
<< tk
->shift
;
57 tk_normalize_xtime(tk
);
60 static void tk_set_wall_to_mono(struct timekeeper
*tk
, struct timespec wtm
)
65 * Verify consistency of: offset_real = -wall_to_monotonic
66 * before modifying anything
68 set_normalized_timespec(&tmp
, -tk
->wall_to_monotonic
.tv_sec
,
69 -tk
->wall_to_monotonic
.tv_nsec
);
70 WARN_ON_ONCE(tk
->offs_real
.tv64
!= timespec_to_ktime(tmp
).tv64
);
71 tk
->wall_to_monotonic
= wtm
;
72 set_normalized_timespec(&tmp
, -wtm
.tv_sec
, -wtm
.tv_nsec
);
73 tk
->offs_real
= timespec_to_ktime(tmp
);
74 tk
->offs_tai
= ktime_sub(tk
->offs_real
, ktime_set(tk
->tai_offset
, 0));
77 static void tk_set_sleep_time(struct timekeeper
*tk
, struct timespec t
)
79 /* Verify consistency before modifying */
80 WARN_ON_ONCE(tk
->offs_boot
.tv64
!= timespec_to_ktime(tk
->total_sleep_time
).tv64
);
82 tk
->total_sleep_time
= t
;
83 tk
->offs_boot
= timespec_to_ktime(t
);
87 * timekeeper_setup_internals - Set up internals to use clocksource clock.
89 * @clock: Pointer to clocksource.
91 * Calculates a fixed cycle/nsec interval for a given clocksource/adjustment
92 * pair and interval request.
94 * Unless you're the timekeeping code, you should not be using this!
96 static void tk_setup_internals(struct timekeeper
*tk
, struct clocksource
*clock
)
100 struct clocksource
*old_clock
;
102 old_clock
= tk
->clock
;
104 clock
->cycle_last
= clock
->read(clock
);
106 /* Do the ns -> cycle conversion first, using original mult */
107 tmp
= NTP_INTERVAL_LENGTH
;
108 tmp
<<= clock
->shift
;
110 tmp
+= clock
->mult
/2;
111 do_div(tmp
, clock
->mult
);
115 interval
= (cycle_t
) tmp
;
116 tk
->cycle_interval
= interval
;
118 /* Go back from cycles -> shifted ns */
119 tk
->xtime_interval
= (u64
) interval
* clock
->mult
;
120 tk
->xtime_remainder
= ntpinterval
- tk
->xtime_interval
;
122 ((u64
) interval
* clock
->mult
) >> clock
->shift
;
124 /* if changing clocks, convert xtime_nsec shift units */
126 int shift_change
= clock
->shift
- old_clock
->shift
;
127 if (shift_change
< 0)
128 tk
->xtime_nsec
>>= -shift_change
;
130 tk
->xtime_nsec
<<= shift_change
;
132 tk
->shift
= clock
->shift
;
135 tk
->ntp_error_shift
= NTP_SCALE_SHIFT
- clock
->shift
;
138 * The timekeeper keeps its own mult values for the currently
139 * active clocksource. These value will be adjusted via NTP
140 * to counteract clock drifting.
142 tk
->mult
= clock
->mult
;
145 /* Timekeeper helper functions. */
147 #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
148 u32 (*arch_gettimeoffset
)(void);
150 u32
get_arch_timeoffset(void)
152 if (likely(arch_gettimeoffset
))
153 return arch_gettimeoffset();
157 static inline u32
get_arch_timeoffset(void) { return 0; }
160 static inline s64
timekeeping_get_ns(struct timekeeper
*tk
)
162 cycle_t cycle_now
, cycle_delta
;
163 struct clocksource
*clock
;
166 /* read clocksource: */
168 cycle_now
= clock
->read(clock
);
170 /* calculate the delta since the last update_wall_time: */
171 cycle_delta
= (cycle_now
- clock
->cycle_last
) & clock
->mask
;
173 nsec
= cycle_delta
* tk
->mult
+ tk
->xtime_nsec
;
176 /* If arch requires, add in get_arch_timeoffset() */
177 return nsec
+ get_arch_timeoffset();
180 static inline s64
timekeeping_get_ns_raw(struct timekeeper
*tk
)
182 cycle_t cycle_now
, cycle_delta
;
183 struct clocksource
*clock
;
186 /* read clocksource: */
188 cycle_now
= clock
->read(clock
);
190 /* calculate the delta since the last update_wall_time: */
191 cycle_delta
= (cycle_now
- clock
->cycle_last
) & clock
->mask
;
193 /* convert delta to nanoseconds. */
194 nsec
= clocksource_cyc2ns(cycle_delta
, clock
->mult
, clock
->shift
);
196 /* If arch requires, add in get_arch_timeoffset() */
197 return nsec
+ get_arch_timeoffset();
200 static RAW_NOTIFIER_HEAD(pvclock_gtod_chain
);
202 static void update_pvclock_gtod(struct timekeeper
*tk
)
204 raw_notifier_call_chain(&pvclock_gtod_chain
, 0, tk
);
208 * pvclock_gtod_register_notifier - register a pvclock timedata update listener
210 int pvclock_gtod_register_notifier(struct notifier_block
*nb
)
212 struct timekeeper
*tk
= &timekeeper
;
216 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
217 ret
= raw_notifier_chain_register(&pvclock_gtod_chain
, nb
);
218 update_pvclock_gtod(tk
);
219 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
223 EXPORT_SYMBOL_GPL(pvclock_gtod_register_notifier
);
226 * pvclock_gtod_unregister_notifier - unregister a pvclock
227 * timedata update listener
229 int pvclock_gtod_unregister_notifier(struct notifier_block
*nb
)
234 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
235 ret
= raw_notifier_chain_unregister(&pvclock_gtod_chain
, nb
);
236 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
240 EXPORT_SYMBOL_GPL(pvclock_gtod_unregister_notifier
);
242 /* must hold timekeeper_lock */
243 static void timekeeping_update(struct timekeeper
*tk
, bool clearntp
)
250 update_pvclock_gtod(tk
);
254 * timekeeping_forward_now - update clock to the current time
256 * Forward the current clock to update its state since the last call to
257 * update_wall_time(). This is useful before significant clock changes,
258 * as it avoids having to deal with this time offset explicitly.
260 static void timekeeping_forward_now(struct timekeeper
*tk
)
262 cycle_t cycle_now
, cycle_delta
;
263 struct clocksource
*clock
;
267 cycle_now
= clock
->read(clock
);
268 cycle_delta
= (cycle_now
- clock
->cycle_last
) & clock
->mask
;
269 clock
->cycle_last
= cycle_now
;
271 tk
->xtime_nsec
+= cycle_delta
* tk
->mult
;
273 /* If arch requires, add in get_arch_timeoffset() */
274 tk
->xtime_nsec
+= (u64
)get_arch_timeoffset() << tk
->shift
;
276 tk_normalize_xtime(tk
);
278 nsec
= clocksource_cyc2ns(cycle_delta
, clock
->mult
, clock
->shift
);
279 timespec_add_ns(&tk
->raw_time
, nsec
);
283 * __getnstimeofday - Returns the time of day in a timespec.
284 * @ts: pointer to the timespec to be set
286 * Updates the time of day in the timespec.
287 * Returns 0 on success, or -ve when suspended (timespec will be undefined).
289 int __getnstimeofday(struct timespec
*ts
)
291 struct timekeeper
*tk
= &timekeeper
;
296 seq
= read_seqcount_begin(&timekeeper_seq
);
298 ts
->tv_sec
= tk
->xtime_sec
;
299 nsecs
= timekeeping_get_ns(tk
);
301 } while (read_seqcount_retry(&timekeeper_seq
, seq
));
304 timespec_add_ns(ts
, nsecs
);
307 * Do not bail out early, in case there were callers still using
308 * the value, even in the face of the WARN_ON.
310 if (unlikely(timekeeping_suspended
))
314 EXPORT_SYMBOL(__getnstimeofday
);
317 * getnstimeofday - Returns the time of day in a timespec.
318 * @ts: pointer to the timespec to be set
320 * Returns the time of day in a timespec (WARN if suspended).
322 void getnstimeofday(struct timespec
*ts
)
324 WARN_ON(__getnstimeofday(ts
));
326 EXPORT_SYMBOL(getnstimeofday
);
328 ktime_t
ktime_get(void)
330 struct timekeeper
*tk
= &timekeeper
;
334 WARN_ON(timekeeping_suspended
);
337 seq
= read_seqcount_begin(&timekeeper_seq
);
338 secs
= tk
->xtime_sec
+ tk
->wall_to_monotonic
.tv_sec
;
339 nsecs
= timekeeping_get_ns(tk
) + tk
->wall_to_monotonic
.tv_nsec
;
341 } while (read_seqcount_retry(&timekeeper_seq
, seq
));
343 * Use ktime_set/ktime_add_ns to create a proper ktime on
344 * 32-bit architectures without CONFIG_KTIME_SCALAR.
346 return ktime_add_ns(ktime_set(secs
, 0), nsecs
);
348 EXPORT_SYMBOL_GPL(ktime_get
);
351 * ktime_get_ts - get the monotonic clock in timespec format
352 * @ts: pointer to timespec variable
354 * The function calculates the monotonic clock from the realtime
355 * clock and the wall_to_monotonic offset and stores the result
356 * in normalized timespec format in the variable pointed to by @ts.
358 void ktime_get_ts(struct timespec
*ts
)
360 struct timekeeper
*tk
= &timekeeper
;
361 struct timespec tomono
;
365 WARN_ON(timekeeping_suspended
);
368 seq
= read_seqcount_begin(&timekeeper_seq
);
369 ts
->tv_sec
= tk
->xtime_sec
;
370 nsec
= timekeeping_get_ns(tk
);
371 tomono
= tk
->wall_to_monotonic
;
373 } while (read_seqcount_retry(&timekeeper_seq
, seq
));
375 ts
->tv_sec
+= tomono
.tv_sec
;
377 timespec_add_ns(ts
, nsec
+ tomono
.tv_nsec
);
379 EXPORT_SYMBOL_GPL(ktime_get_ts
);
383 * timekeeping_clocktai - Returns the TAI time of day in a timespec
384 * @ts: pointer to the timespec to be set
386 * Returns the time of day in a timespec.
388 void timekeeping_clocktai(struct timespec
*ts
)
390 struct timekeeper
*tk
= &timekeeper
;
394 WARN_ON(timekeeping_suspended
);
397 seq
= read_seqcount_begin(&timekeeper_seq
);
399 ts
->tv_sec
= tk
->xtime_sec
+ tk
->tai_offset
;
400 nsecs
= timekeeping_get_ns(tk
);
402 } while (read_seqcount_retry(&timekeeper_seq
, seq
));
405 timespec_add_ns(ts
, nsecs
);
408 EXPORT_SYMBOL(timekeeping_clocktai
);
412 * ktime_get_clocktai - Returns the TAI time of day in a ktime
414 * Returns the time of day in a ktime.
416 ktime_t
ktime_get_clocktai(void)
420 timekeeping_clocktai(&ts
);
421 return timespec_to_ktime(ts
);
423 EXPORT_SYMBOL(ktime_get_clocktai
);
425 #ifdef CONFIG_NTP_PPS
428 * getnstime_raw_and_real - get day and raw monotonic time in timespec format
429 * @ts_raw: pointer to the timespec to be set to raw monotonic time
430 * @ts_real: pointer to the timespec to be set to the time of day
432 * This function reads both the time of day and raw monotonic time at the
433 * same time atomically and stores the resulting timestamps in timespec
436 void getnstime_raw_and_real(struct timespec
*ts_raw
, struct timespec
*ts_real
)
438 struct timekeeper
*tk
= &timekeeper
;
440 s64 nsecs_raw
, nsecs_real
;
442 WARN_ON_ONCE(timekeeping_suspended
);
445 seq
= read_seqcount_begin(&timekeeper_seq
);
447 *ts_raw
= tk
->raw_time
;
448 ts_real
->tv_sec
= tk
->xtime_sec
;
449 ts_real
->tv_nsec
= 0;
451 nsecs_raw
= timekeeping_get_ns_raw(tk
);
452 nsecs_real
= timekeeping_get_ns(tk
);
454 } while (read_seqcount_retry(&timekeeper_seq
, seq
));
456 timespec_add_ns(ts_raw
, nsecs_raw
);
457 timespec_add_ns(ts_real
, nsecs_real
);
459 EXPORT_SYMBOL(getnstime_raw_and_real
);
461 #endif /* CONFIG_NTP_PPS */
464 * do_gettimeofday - Returns the time of day in a timeval
465 * @tv: pointer to the timeval to be set
467 * NOTE: Users should be converted to using getnstimeofday()
469 void do_gettimeofday(struct timeval
*tv
)
473 getnstimeofday(&now
);
474 tv
->tv_sec
= now
.tv_sec
;
475 tv
->tv_usec
= now
.tv_nsec
/1000;
477 EXPORT_SYMBOL(do_gettimeofday
);
480 * do_settimeofday - Sets the time of day
481 * @tv: pointer to the timespec variable containing the new time
483 * Sets the time of day to the new time and update NTP and notify hrtimers
485 int do_settimeofday(const struct timespec
*tv
)
487 struct timekeeper
*tk
= &timekeeper
;
488 struct timespec ts_delta
, xt
;
491 if (!timespec_valid_strict(tv
))
494 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
495 write_seqcount_begin(&timekeeper_seq
);
497 timekeeping_forward_now(tk
);
500 ts_delta
.tv_sec
= tv
->tv_sec
- xt
.tv_sec
;
501 ts_delta
.tv_nsec
= tv
->tv_nsec
- xt
.tv_nsec
;
503 tk_set_wall_to_mono(tk
, timespec_sub(tk
->wall_to_monotonic
, ts_delta
));
505 tk_set_xtime(tk
, tv
);
507 timekeeping_update(tk
, true);
509 write_seqcount_end(&timekeeper_seq
);
510 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
512 /* signal hrtimers about time change */
517 EXPORT_SYMBOL(do_settimeofday
);
520 * timekeeping_inject_offset - Adds or subtracts from the current time.
521 * @tv: pointer to the timespec variable containing the offset
523 * Adds or subtracts an offset value from the current time.
525 int timekeeping_inject_offset(struct timespec
*ts
)
527 struct timekeeper
*tk
= &timekeeper
;
532 if ((unsigned long)ts
->tv_nsec
>= NSEC_PER_SEC
)
535 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
536 write_seqcount_begin(&timekeeper_seq
);
538 timekeeping_forward_now(tk
);
540 /* Make sure the proposed value is valid */
541 tmp
= timespec_add(tk_xtime(tk
), *ts
);
542 if (!timespec_valid_strict(&tmp
)) {
547 tk_xtime_add(tk
, ts
);
548 tk_set_wall_to_mono(tk
, timespec_sub(tk
->wall_to_monotonic
, *ts
));
550 error
: /* even if we error out, we forwarded the time, so call update */
551 timekeeping_update(tk
, true);
553 write_seqcount_end(&timekeeper_seq
);
554 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
556 /* signal hrtimers about time change */
561 EXPORT_SYMBOL(timekeeping_inject_offset
);
565 * timekeeping_get_tai_offset - Returns current TAI offset from UTC
568 s32
timekeeping_get_tai_offset(void)
570 struct timekeeper
*tk
= &timekeeper
;
575 seq
= read_seqcount_begin(&timekeeper_seq
);
576 ret
= tk
->tai_offset
;
577 } while (read_seqcount_retry(&timekeeper_seq
, seq
));
583 * __timekeeping_set_tai_offset - Lock free worker function
586 static void __timekeeping_set_tai_offset(struct timekeeper
*tk
, s32 tai_offset
)
588 tk
->tai_offset
= tai_offset
;
589 tk
->offs_tai
= ktime_sub(tk
->offs_real
, ktime_set(tai_offset
, 0));
593 * timekeeping_set_tai_offset - Sets the current TAI offset from UTC
596 void timekeeping_set_tai_offset(s32 tai_offset
)
598 struct timekeeper
*tk
= &timekeeper
;
601 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
602 write_seqcount_begin(&timekeeper_seq
);
603 __timekeeping_set_tai_offset(tk
, tai_offset
);
604 write_seqcount_end(&timekeeper_seq
);
605 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
609 * change_clocksource - Swaps clocksources if a new one is available
611 * Accumulates current time interval and initializes new clocksource
613 static int change_clocksource(void *data
)
615 struct timekeeper
*tk
= &timekeeper
;
616 struct clocksource
*new, *old
;
619 new = (struct clocksource
*) data
;
621 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
622 write_seqcount_begin(&timekeeper_seq
);
624 timekeeping_forward_now(tk
);
625 if (!new->enable
|| new->enable(new) == 0) {
627 tk_setup_internals(tk
, new);
631 timekeeping_update(tk
, true);
633 write_seqcount_end(&timekeeper_seq
);
634 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
640 * timekeeping_notify - Install a new clock source
641 * @clock: pointer to the clock source
643 * This function is called from clocksource.c after a new, better clock
644 * source has been registered. The caller holds the clocksource_mutex.
646 void timekeeping_notify(struct clocksource
*clock
)
648 struct timekeeper
*tk
= &timekeeper
;
650 if (tk
->clock
== clock
)
652 stop_machine(change_clocksource
, clock
, NULL
);
657 * ktime_get_real - get the real (wall-) time in ktime_t format
659 * returns the time in ktime_t format
661 ktime_t
ktime_get_real(void)
665 getnstimeofday(&now
);
667 return timespec_to_ktime(now
);
669 EXPORT_SYMBOL_GPL(ktime_get_real
);
672 * getrawmonotonic - Returns the raw monotonic time in a timespec
673 * @ts: pointer to the timespec to be set
675 * Returns the raw monotonic time (completely un-modified by ntp)
677 void getrawmonotonic(struct timespec
*ts
)
679 struct timekeeper
*tk
= &timekeeper
;
684 seq
= read_seqcount_begin(&timekeeper_seq
);
685 nsecs
= timekeeping_get_ns_raw(tk
);
688 } while (read_seqcount_retry(&timekeeper_seq
, seq
));
690 timespec_add_ns(ts
, nsecs
);
692 EXPORT_SYMBOL(getrawmonotonic
);
695 * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres
697 int timekeeping_valid_for_hres(void)
699 struct timekeeper
*tk
= &timekeeper
;
704 seq
= read_seqcount_begin(&timekeeper_seq
);
706 ret
= tk
->clock
->flags
& CLOCK_SOURCE_VALID_FOR_HRES
;
708 } while (read_seqcount_retry(&timekeeper_seq
, seq
));
714 * timekeeping_max_deferment - Returns max time the clocksource can be deferred
716 u64
timekeeping_max_deferment(void)
718 struct timekeeper
*tk
= &timekeeper
;
723 seq
= read_seqcount_begin(&timekeeper_seq
);
725 ret
= tk
->clock
->max_idle_ns
;
727 } while (read_seqcount_retry(&timekeeper_seq
, seq
));
733 * read_persistent_clock - Return time from the persistent clock.
735 * Weak dummy function for arches that do not yet support it.
736 * Reads the time from the battery backed persistent clock.
737 * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported.
739 * XXX - Do be sure to remove it once all arches implement it.
741 void __attribute__((weak
)) read_persistent_clock(struct timespec
*ts
)
748 * read_boot_clock - Return time of the system start.
750 * Weak dummy function for arches that do not yet support it.
751 * Function to read the exact time the system has been started.
752 * Returns a timespec with tv_sec=0 and tv_nsec=0 if unsupported.
754 * XXX - Do be sure to remove it once all arches implement it.
756 void __attribute__((weak
)) read_boot_clock(struct timespec
*ts
)
763 * timekeeping_init - Initializes the clocksource and common timekeeping values
765 void __init
timekeeping_init(void)
767 struct timekeeper
*tk
= &timekeeper
;
768 struct clocksource
*clock
;
770 struct timespec now
, boot
, tmp
;
772 read_persistent_clock(&now
);
774 if (!timespec_valid_strict(&now
)) {
775 pr_warn("WARNING: Persistent clock returned invalid value!\n"
776 " Check your CMOS/BIOS settings.\n");
779 } else if (now
.tv_sec
|| now
.tv_nsec
)
780 persistent_clock_exist
= true;
782 read_boot_clock(&boot
);
783 if (!timespec_valid_strict(&boot
)) {
784 pr_warn("WARNING: Boot clock returned invalid value!\n"
785 " Check your CMOS/BIOS settings.\n");
792 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
793 write_seqcount_begin(&timekeeper_seq
);
794 clock
= clocksource_default_clock();
796 clock
->enable(clock
);
797 tk_setup_internals(tk
, clock
);
799 tk_set_xtime(tk
, &now
);
800 tk
->raw_time
.tv_sec
= 0;
801 tk
->raw_time
.tv_nsec
= 0;
802 if (boot
.tv_sec
== 0 && boot
.tv_nsec
== 0)
805 set_normalized_timespec(&tmp
, -boot
.tv_sec
, -boot
.tv_nsec
);
806 tk_set_wall_to_mono(tk
, tmp
);
810 tk_set_sleep_time(tk
, tmp
);
812 write_seqcount_end(&timekeeper_seq
);
813 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
816 /* time in seconds when suspend began */
817 static struct timespec timekeeping_suspend_time
;
820 * __timekeeping_inject_sleeptime - Internal function to add sleep interval
821 * @delta: pointer to a timespec delta value
823 * Takes a timespec offset measuring a suspend interval and properly
824 * adds the sleep offset to the timekeeping variables.
826 static void __timekeeping_inject_sleeptime(struct timekeeper
*tk
,
827 struct timespec
*delta
)
829 if (!timespec_valid_strict(delta
)) {
830 printk(KERN_WARNING
"__timekeeping_inject_sleeptime: Invalid "
831 "sleep delta value!\n");
834 tk_xtime_add(tk
, delta
);
835 tk_set_wall_to_mono(tk
, timespec_sub(tk
->wall_to_monotonic
, *delta
));
836 tk_set_sleep_time(tk
, timespec_add(tk
->total_sleep_time
, *delta
));
840 * timekeeping_inject_sleeptime - Adds suspend interval to timeekeeping values
841 * @delta: pointer to a timespec delta value
843 * This hook is for architectures that cannot support read_persistent_clock
844 * because their RTC/persistent clock is only accessible when irqs are enabled.
846 * This function should only be called by rtc_resume(), and allows
847 * a suspend offset to be injected into the timekeeping values.
849 void timekeeping_inject_sleeptime(struct timespec
*delta
)
851 struct timekeeper
*tk
= &timekeeper
;
855 * Make sure we don't set the clock twice, as timekeeping_resume()
858 if (has_persistent_clock())
861 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
862 write_seqcount_begin(&timekeeper_seq
);
864 timekeeping_forward_now(tk
);
866 __timekeeping_inject_sleeptime(tk
, delta
);
868 timekeeping_update(tk
, true);
870 write_seqcount_end(&timekeeper_seq
);
871 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
873 /* signal hrtimers about time change */
878 * timekeeping_resume - Resumes the generic timekeeping subsystem.
880 * This is for the generic clocksource timekeeping.
881 * xtime/wall_to_monotonic/jiffies/etc are
882 * still managed by arch specific suspend/resume code.
884 static void timekeeping_resume(void)
886 struct timekeeper
*tk
= &timekeeper
;
887 struct clocksource
*clock
= tk
->clock
;
889 struct timespec ts_new
, ts_delta
;
890 cycle_t cycle_now
, cycle_delta
;
891 bool suspendtime_found
= false;
893 read_persistent_clock(&ts_new
);
895 clockevents_resume();
896 clocksource_resume();
898 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
899 write_seqcount_begin(&timekeeper_seq
);
902 * After system resumes, we need to calculate the suspended time and
903 * compensate it for the OS time. There are 3 sources that could be
904 * used: Nonstop clocksource during suspend, persistent clock and rtc
907 * One specific platform may have 1 or 2 or all of them, and the
908 * preference will be:
909 * suspend-nonstop clocksource -> persistent clock -> rtc
910 * The less preferred source will only be tried if there is no better
911 * usable source. The rtc part is handled separately in rtc core code.
913 cycle_now
= clock
->read(clock
);
914 if ((clock
->flags
& CLOCK_SOURCE_SUSPEND_NONSTOP
) &&
915 cycle_now
> clock
->cycle_last
) {
916 u64 num
, max
= ULLONG_MAX
;
917 u32 mult
= clock
->mult
;
918 u32 shift
= clock
->shift
;
921 cycle_delta
= (cycle_now
- clock
->cycle_last
) & clock
->mask
;
924 * "cycle_delta * mutl" may cause 64 bits overflow, if the
925 * suspended time is too long. In that case we need do the
926 * 64 bits math carefully
929 if (cycle_delta
> max
) {
930 num
= div64_u64(cycle_delta
, max
);
931 nsec
= (((u64
) max
* mult
) >> shift
) * num
;
932 cycle_delta
-= num
* max
;
934 nsec
+= ((u64
) cycle_delta
* mult
) >> shift
;
936 ts_delta
= ns_to_timespec(nsec
);
937 suspendtime_found
= true;
938 } else if (timespec_compare(&ts_new
, &timekeeping_suspend_time
) > 0) {
939 ts_delta
= timespec_sub(ts_new
, timekeeping_suspend_time
);
940 suspendtime_found
= true;
943 if (suspendtime_found
)
944 __timekeeping_inject_sleeptime(tk
, &ts_delta
);
946 /* Re-base the last cycle value */
947 clock
->cycle_last
= cycle_now
;
949 timekeeping_suspended
= 0;
950 timekeeping_update(tk
, false);
951 write_seqcount_end(&timekeeper_seq
);
952 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
954 touch_softlockup_watchdog();
956 clockevents_notify(CLOCK_EVT_NOTIFY_RESUME
, NULL
);
958 /* Resume hrtimers */
962 static int timekeeping_suspend(void)
964 struct timekeeper
*tk
= &timekeeper
;
966 struct timespec delta
, delta_delta
;
967 static struct timespec old_delta
;
969 read_persistent_clock(&timekeeping_suspend_time
);
971 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
972 write_seqcount_begin(&timekeeper_seq
);
973 timekeeping_forward_now(tk
);
974 timekeeping_suspended
= 1;
977 * To avoid drift caused by repeated suspend/resumes,
978 * which each can add ~1 second drift error,
979 * try to compensate so the difference in system time
980 * and persistent_clock time stays close to constant.
982 delta
= timespec_sub(tk_xtime(tk
), timekeeping_suspend_time
);
983 delta_delta
= timespec_sub(delta
, old_delta
);
984 if (abs(delta_delta
.tv_sec
) >= 2) {
986 * if delta_delta is too large, assume time correction
987 * has occured and set old_delta to the current delta.
991 /* Otherwise try to adjust old_system to compensate */
992 timekeeping_suspend_time
=
993 timespec_add(timekeeping_suspend_time
, delta_delta
);
995 write_seqcount_end(&timekeeper_seq
);
996 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
998 clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND
, NULL
);
999 clocksource_suspend();
1000 clockevents_suspend();
1005 /* sysfs resume/suspend bits for timekeeping */
1006 static struct syscore_ops timekeeping_syscore_ops
= {
1007 .resume
= timekeeping_resume
,
1008 .suspend
= timekeeping_suspend
,
1011 static int __init
timekeeping_init_ops(void)
1013 register_syscore_ops(&timekeeping_syscore_ops
);
1017 device_initcall(timekeeping_init_ops
);
1020 * If the error is already larger, we look ahead even further
1021 * to compensate for late or lost adjustments.
1023 static __always_inline
int timekeeping_bigadjust(struct timekeeper
*tk
,
1024 s64 error
, s64
*interval
,
1028 u32 look_ahead
, adj
;
1032 * Use the current error value to determine how much to look ahead.
1033 * The larger the error the slower we adjust for it to avoid problems
1034 * with losing too many ticks, otherwise we would overadjust and
1035 * produce an even larger error. The smaller the adjustment the
1036 * faster we try to adjust for it, as lost ticks can do less harm
1037 * here. This is tuned so that an error of about 1 msec is adjusted
1038 * within about 1 sec (or 2^20 nsec in 2^SHIFT_HZ ticks).
1040 error2
= tk
->ntp_error
>> (NTP_SCALE_SHIFT
+ 22 - 2 * SHIFT_HZ
);
1041 error2
= abs(error2
);
1042 for (look_ahead
= 0; error2
> 0; look_ahead
++)
1046 * Now calculate the error in (1 << look_ahead) ticks, but first
1047 * remove the single look ahead already included in the error.
1049 tick_error
= ntp_tick_length() >> (tk
->ntp_error_shift
+ 1);
1050 tick_error
-= tk
->xtime_interval
>> 1;
1051 error
= ((error
- tick_error
) >> look_ahead
) + tick_error
;
1053 /* Finally calculate the adjustment shift value. */
1058 *interval
= -*interval
;
1062 for (adj
= 0; error
> i
; adj
++)
1071 * Adjust the multiplier to reduce the error value,
1072 * this is optimized for the most common adjustments of -1,0,1,
1073 * for other values we can do a bit more work.
1075 static void timekeeping_adjust(struct timekeeper
*tk
, s64 offset
)
1077 s64 error
, interval
= tk
->cycle_interval
;
1081 * The point of this is to check if the error is greater than half
1084 * First we shift it down from NTP_SHIFT to clocksource->shifted nsecs.
1086 * Note we subtract one in the shift, so that error is really error*2.
1087 * This "saves" dividing(shifting) interval twice, but keeps the
1088 * (error > interval) comparison as still measuring if error is
1089 * larger than half an interval.
1091 * Note: It does not "save" on aggravation when reading the code.
1093 error
= tk
->ntp_error
>> (tk
->ntp_error_shift
- 1);
1094 if (error
> interval
) {
1096 * We now divide error by 4(via shift), which checks if
1097 * the error is greater than twice the interval.
1098 * If it is greater, we need a bigadjust, if its smaller,
1099 * we can adjust by 1.
1103 * XXX - In update_wall_time, we round up to the next
1104 * nanosecond, and store the amount rounded up into
1105 * the error. This causes the likely below to be unlikely.
1107 * The proper fix is to avoid rounding up by using
1108 * the high precision tk->xtime_nsec instead of
1109 * xtime.tv_nsec everywhere. Fixing this will take some
1112 if (likely(error
<= interval
))
1115 adj
= timekeeping_bigadjust(tk
, error
, &interval
, &offset
);
1117 if (error
< -interval
) {
1118 /* See comment above, this is just switched for the negative */
1120 if (likely(error
>= -interval
)) {
1122 interval
= -interval
;
1125 adj
= timekeeping_bigadjust(tk
, error
, &interval
, &offset
);
1132 if (unlikely(tk
->clock
->maxadj
&&
1133 (tk
->mult
+ adj
> tk
->clock
->mult
+ tk
->clock
->maxadj
))) {
1134 printk_once(KERN_WARNING
1135 "Adjusting %s more than 11%% (%ld vs %ld)\n",
1136 tk
->clock
->name
, (long)tk
->mult
+ adj
,
1137 (long)tk
->clock
->mult
+ tk
->clock
->maxadj
);
1140 * So the following can be confusing.
1142 * To keep things simple, lets assume adj == 1 for now.
1144 * When adj != 1, remember that the interval and offset values
1145 * have been appropriately scaled so the math is the same.
1147 * The basic idea here is that we're increasing the multiplier
1148 * by one, this causes the xtime_interval to be incremented by
1149 * one cycle_interval. This is because:
1150 * xtime_interval = cycle_interval * mult
1151 * So if mult is being incremented by one:
1152 * xtime_interval = cycle_interval * (mult + 1)
1154 * xtime_interval = (cycle_interval * mult) + cycle_interval
1155 * Which can be shortened to:
1156 * xtime_interval += cycle_interval
1158 * So offset stores the non-accumulated cycles. Thus the current
1159 * time (in shifted nanoseconds) is:
1160 * now = (offset * adj) + xtime_nsec
1161 * Now, even though we're adjusting the clock frequency, we have
1162 * to keep time consistent. In other words, we can't jump back
1163 * in time, and we also want to avoid jumping forward in time.
1165 * So given the same offset value, we need the time to be the same
1166 * both before and after the freq adjustment.
1167 * now = (offset * adj_1) + xtime_nsec_1
1168 * now = (offset * adj_2) + xtime_nsec_2
1170 * (offset * adj_1) + xtime_nsec_1 =
1171 * (offset * adj_2) + xtime_nsec_2
1175 * (offset * adj_1) + xtime_nsec_1 =
1176 * (offset * (adj_1+1)) + xtime_nsec_2
1177 * (offset * adj_1) + xtime_nsec_1 =
1178 * (offset * adj_1) + offset + xtime_nsec_2
1179 * Canceling the sides:
1180 * xtime_nsec_1 = offset + xtime_nsec_2
1182 * xtime_nsec_2 = xtime_nsec_1 - offset
1183 * Which simplfies to:
1184 * xtime_nsec -= offset
1186 * XXX - TODO: Doc ntp_error calculation.
1189 tk
->xtime_interval
+= interval
;
1190 tk
->xtime_nsec
-= offset
;
1191 tk
->ntp_error
-= (interval
- offset
) << tk
->ntp_error_shift
;
1195 * It may be possible that when we entered this function, xtime_nsec
1196 * was very small. Further, if we're slightly speeding the clocksource
1197 * in the code above, its possible the required corrective factor to
1198 * xtime_nsec could cause it to underflow.
1200 * Now, since we already accumulated the second, cannot simply roll
1201 * the accumulated second back, since the NTP subsystem has been
1202 * notified via second_overflow. So instead we push xtime_nsec forward
1203 * by the amount we underflowed, and add that amount into the error.
1205 * We'll correct this error next time through this function, when
1206 * xtime_nsec is not as small.
1208 if (unlikely((s64
)tk
->xtime_nsec
< 0)) {
1209 s64 neg
= -(s64
)tk
->xtime_nsec
;
1211 tk
->ntp_error
+= neg
<< tk
->ntp_error_shift
;
1217 * accumulate_nsecs_to_secs - Accumulates nsecs into secs
1219 * Helper function that accumulates a the nsecs greater then a second
1220 * from the xtime_nsec field to the xtime_secs field.
1221 * It also calls into the NTP code to handle leapsecond processing.
1224 static inline void accumulate_nsecs_to_secs(struct timekeeper
*tk
)
1226 u64 nsecps
= (u64
)NSEC_PER_SEC
<< tk
->shift
;
1228 while (tk
->xtime_nsec
>= nsecps
) {
1231 tk
->xtime_nsec
-= nsecps
;
1234 /* Figure out if its a leap sec and apply if needed */
1235 leap
= second_overflow(tk
->xtime_sec
);
1236 if (unlikely(leap
)) {
1239 tk
->xtime_sec
+= leap
;
1243 tk_set_wall_to_mono(tk
,
1244 timespec_sub(tk
->wall_to_monotonic
, ts
));
1246 __timekeeping_set_tai_offset(tk
, tk
->tai_offset
- leap
);
1248 clock_was_set_delayed();
1254 * logarithmic_accumulation - shifted accumulation of cycles
1256 * This functions accumulates a shifted interval of cycles into
1257 * into a shifted interval nanoseconds. Allows for O(log) accumulation
1260 * Returns the unconsumed cycles.
1262 static cycle_t
logarithmic_accumulation(struct timekeeper
*tk
, cycle_t offset
,
1265 cycle_t interval
= tk
->cycle_interval
<< shift
;
1268 /* If the offset is smaller then a shifted interval, do nothing */
1269 if (offset
< interval
)
1272 /* Accumulate one shifted interval */
1274 tk
->clock
->cycle_last
+= interval
;
1276 tk
->xtime_nsec
+= tk
->xtime_interval
<< shift
;
1277 accumulate_nsecs_to_secs(tk
);
1279 /* Accumulate raw time */
1280 raw_nsecs
= (u64
)tk
->raw_interval
<< shift
;
1281 raw_nsecs
+= tk
->raw_time
.tv_nsec
;
1282 if (raw_nsecs
>= NSEC_PER_SEC
) {
1283 u64 raw_secs
= raw_nsecs
;
1284 raw_nsecs
= do_div(raw_secs
, NSEC_PER_SEC
);
1285 tk
->raw_time
.tv_sec
+= raw_secs
;
1287 tk
->raw_time
.tv_nsec
= raw_nsecs
;
1289 /* Accumulate error between NTP and clock interval */
1290 tk
->ntp_error
+= ntp_tick_length() << shift
;
1291 tk
->ntp_error
-= (tk
->xtime_interval
+ tk
->xtime_remainder
) <<
1292 (tk
->ntp_error_shift
+ shift
);
1297 #ifdef CONFIG_GENERIC_TIME_VSYSCALL_OLD
1298 static inline void old_vsyscall_fixup(struct timekeeper
*tk
)
1303 * Store only full nanoseconds into xtime_nsec after rounding
1304 * it up and add the remainder to the error difference.
1305 * XXX - This is necessary to avoid small 1ns inconsistnecies caused
1306 * by truncating the remainder in vsyscalls. However, it causes
1307 * additional work to be done in timekeeping_adjust(). Once
1308 * the vsyscall implementations are converted to use xtime_nsec
1309 * (shifted nanoseconds), and CONFIG_GENERIC_TIME_VSYSCALL_OLD
1310 * users are removed, this can be killed.
1312 remainder
= tk
->xtime_nsec
& ((1ULL << tk
->shift
) - 1);
1313 tk
->xtime_nsec
-= remainder
;
1314 tk
->xtime_nsec
+= 1ULL << tk
->shift
;
1315 tk
->ntp_error
+= remainder
<< tk
->ntp_error_shift
;
1319 #define old_vsyscall_fixup(tk)
1325 * update_wall_time - Uses the current clocksource to increment the wall time
1328 static void update_wall_time(void)
1330 struct clocksource
*clock
;
1331 struct timekeeper
*tk
= &timekeeper
;
1333 int shift
= 0, maxshift
;
1334 unsigned long flags
;
1336 raw_spin_lock_irqsave(&timekeeper_lock
, flags
);
1337 write_seqcount_begin(&timekeeper_seq
);
1339 /* Make sure we're fully resumed: */
1340 if (unlikely(timekeeping_suspended
))
1345 #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
1346 offset
= tk
->cycle_interval
;
1348 offset
= (clock
->read(clock
) - clock
->cycle_last
) & clock
->mask
;
1351 /* Check if there's really nothing to do */
1352 if (offset
< tk
->cycle_interval
)
1356 * With NO_HZ we may have to accumulate many cycle_intervals
1357 * (think "ticks") worth of time at once. To do this efficiently,
1358 * we calculate the largest doubling multiple of cycle_intervals
1359 * that is smaller than the offset. We then accumulate that
1360 * chunk in one go, and then try to consume the next smaller
1363 shift
= ilog2(offset
) - ilog2(tk
->cycle_interval
);
1364 shift
= max(0, shift
);
1365 /* Bound shift to one less than what overflows tick_length */
1366 maxshift
= (64 - (ilog2(ntp_tick_length())+1)) - 1;
1367 shift
= min(shift
, maxshift
);
1368 while (offset
>= tk
->cycle_interval
) {
1369 offset
= logarithmic_accumulation(tk
, offset
, shift
);
1370 if (offset
< tk
->cycle_interval
<<shift
)
1374 /* correct the clock when NTP error is too big */
1375 timekeeping_adjust(tk
, offset
);
1378 * XXX This can be killed once everyone converts
1379 * to the new update_vsyscall.
1381 old_vsyscall_fixup(tk
);
1384 * Finally, make sure that after the rounding
1385 * xtime_nsec isn't larger than NSEC_PER_SEC
1387 accumulate_nsecs_to_secs(tk
);
1389 timekeeping_update(tk
, false);
1392 write_seqcount_end(&timekeeper_seq
);
1393 raw_spin_unlock_irqrestore(&timekeeper_lock
, flags
);
1398 * getboottime - Return the real time of system boot.
1399 * @ts: pointer to the timespec to be set
1401 * Returns the wall-time of boot in a timespec.
1403 * This is based on the wall_to_monotonic offset and the total suspend
1404 * time. Calls to settimeofday will affect the value returned (which
1405 * basically means that however wrong your real time clock is at boot time,
1406 * you get the right time here).
1408 void getboottime(struct timespec
*ts
)
1410 struct timekeeper
*tk
= &timekeeper
;
1411 struct timespec boottime
= {
1412 .tv_sec
= tk
->wall_to_monotonic
.tv_sec
+
1413 tk
->total_sleep_time
.tv_sec
,
1414 .tv_nsec
= tk
->wall_to_monotonic
.tv_nsec
+
1415 tk
->total_sleep_time
.tv_nsec
1418 set_normalized_timespec(ts
, -boottime
.tv_sec
, -boottime
.tv_nsec
);
1420 EXPORT_SYMBOL_GPL(getboottime
);
1423 * get_monotonic_boottime - Returns monotonic time since boot
1424 * @ts: pointer to the timespec to be set
1426 * Returns the monotonic time since boot in a timespec.
1428 * This is similar to CLOCK_MONTONIC/ktime_get_ts, but also
1429 * includes the time spent in suspend.
1431 void get_monotonic_boottime(struct timespec
*ts
)
1433 struct timekeeper
*tk
= &timekeeper
;
1434 struct timespec tomono
, sleep
;
1438 WARN_ON(timekeeping_suspended
);
1441 seq
= read_seqcount_begin(&timekeeper_seq
);
1442 ts
->tv_sec
= tk
->xtime_sec
;
1443 nsec
= timekeeping_get_ns(tk
);
1444 tomono
= tk
->wall_to_monotonic
;
1445 sleep
= tk
->total_sleep_time
;
1447 } while (read_seqcount_retry(&timekeeper_seq
, seq
));
1449 ts
->tv_sec
+= tomono
.tv_sec
+ sleep
.tv_sec
;
1451 timespec_add_ns(ts
, nsec
+ tomono
.tv_nsec
+ sleep
.tv_nsec
);
1453 EXPORT_SYMBOL_GPL(get_monotonic_boottime
);
1456 * ktime_get_boottime - Returns monotonic time since boot in a ktime
1458 * Returns the monotonic time since boot in a ktime
1460 * This is similar to CLOCK_MONTONIC/ktime_get, but also
1461 * includes the time spent in suspend.
1463 ktime_t
ktime_get_boottime(void)
1467 get_monotonic_boottime(&ts
);
1468 return timespec_to_ktime(ts
);
1470 EXPORT_SYMBOL_GPL(ktime_get_boottime
);
1473 * monotonic_to_bootbased - Convert the monotonic time to boot based.
1474 * @ts: pointer to the timespec to be converted
1476 void monotonic_to_bootbased(struct timespec
*ts
)
1478 struct timekeeper
*tk
= &timekeeper
;
1480 *ts
= timespec_add(*ts
, tk
->total_sleep_time
);
1482 EXPORT_SYMBOL_GPL(monotonic_to_bootbased
);
1484 unsigned long get_seconds(void)
1486 struct timekeeper
*tk
= &timekeeper
;
1488 return tk
->xtime_sec
;
1490 EXPORT_SYMBOL(get_seconds
);
1492 struct timespec
__current_kernel_time(void)
1494 struct timekeeper
*tk
= &timekeeper
;
1496 return tk_xtime(tk
);
1499 struct timespec
current_kernel_time(void)
1501 struct timekeeper
*tk
= &timekeeper
;
1502 struct timespec now
;
1506 seq
= read_seqcount_begin(&timekeeper_seq
);
1509 } while (read_seqcount_retry(&timekeeper_seq
, seq
));
1513 EXPORT_SYMBOL(current_kernel_time
);
1515 struct timespec
get_monotonic_coarse(void)
1517 struct timekeeper
*tk
= &timekeeper
;
1518 struct timespec now
, mono
;
1522 seq
= read_seqcount_begin(&timekeeper_seq
);
1525 mono
= tk
->wall_to_monotonic
;
1526 } while (read_seqcount_retry(&timekeeper_seq
, seq
));
1528 set_normalized_timespec(&now
, now
.tv_sec
+ mono
.tv_sec
,
1529 now
.tv_nsec
+ mono
.tv_nsec
);
1534 * Must hold jiffies_lock
1536 void do_timer(unsigned long ticks
)
1538 jiffies_64
+= ticks
;
1540 calc_global_load(ticks
);
1544 * get_xtime_and_monotonic_and_sleep_offset() - get xtime, wall_to_monotonic,
1545 * and sleep offsets.
1546 * @xtim: pointer to timespec to be set with xtime
1547 * @wtom: pointer to timespec to be set with wall_to_monotonic
1548 * @sleep: pointer to timespec to be set with time in suspend
1550 void get_xtime_and_monotonic_and_sleep_offset(struct timespec
*xtim
,
1551 struct timespec
*wtom
, struct timespec
*sleep
)
1553 struct timekeeper
*tk
= &timekeeper
;
1557 seq
= read_seqcount_begin(&timekeeper_seq
);
1558 *xtim
= tk_xtime(tk
);
1559 *wtom
= tk
->wall_to_monotonic
;
1560 *sleep
= tk
->total_sleep_time
;
1561 } while (read_seqcount_retry(&timekeeper_seq
, seq
));
1564 #ifdef CONFIG_HIGH_RES_TIMERS
1566 * ktime_get_update_offsets - hrtimer helper
1567 * @offs_real: pointer to storage for monotonic -> realtime offset
1568 * @offs_boot: pointer to storage for monotonic -> boottime offset
1570 * Returns current monotonic time and updates the offsets
1571 * Called from hrtimer_interupt() or retrigger_next_event()
1573 ktime_t
ktime_get_update_offsets(ktime_t
*offs_real
, ktime_t
*offs_boot
,
1576 struct timekeeper
*tk
= &timekeeper
;
1582 seq
= read_seqcount_begin(&timekeeper_seq
);
1584 secs
= tk
->xtime_sec
;
1585 nsecs
= timekeeping_get_ns(tk
);
1587 *offs_real
= tk
->offs_real
;
1588 *offs_boot
= tk
->offs_boot
;
1589 *offs_tai
= tk
->offs_tai
;
1590 } while (read_seqcount_retry(&timekeeper_seq
, seq
));
1592 now
= ktime_add_ns(ktime_set(secs
, 0), nsecs
);
1593 now
= ktime_sub(now
, *offs_real
);
1599 * ktime_get_monotonic_offset() - get wall_to_monotonic in ktime_t format
1601 ktime_t
ktime_get_monotonic_offset(void)
1603 struct timekeeper
*tk
= &timekeeper
;
1605 struct timespec wtom
;
1608 seq
= read_seqcount_begin(&timekeeper_seq
);
1609 wtom
= tk
->wall_to_monotonic
;
1610 } while (read_seqcount_retry(&timekeeper_seq
, seq
));
1612 return timespec_to_ktime(wtom
);
1614 EXPORT_SYMBOL_GPL(ktime_get_monotonic_offset
);
1617 * do_adjtimex() - Accessor function to NTP __do_adjtimex function
1619 int do_adjtimex(struct timex
*txc
)
1625 /* Validate the data before disabling interrupts */
1626 ret
= ntp_validate_timex(txc
);
1630 getnstimeofday(&ts
);
1631 orig_tai
= tai
= timekeeping_get_tai_offset();
1633 ret
= __do_adjtimex(txc
, &ts
, &tai
);
1635 if (tai
!= orig_tai
)
1636 timekeeping_set_tai_offset(tai
);
1641 #ifdef CONFIG_NTP_PPS
1643 * hardpps() - Accessor function to NTP __hardpps function
1645 void hardpps(const struct timespec
*phase_ts
, const struct timespec
*raw_ts
)
1647 __hardpps(phase_ts
, raw_ts
);
1649 EXPORT_SYMBOL(hardpps
);
1653 * xtime_update() - advances the timekeeping infrastructure
1654 * @ticks: number of ticks, that have elapsed since the last call.
1656 * Must be called with interrupts disabled.
1658 void xtime_update(unsigned long ticks
)
1660 write_seqlock(&jiffies_lock
);
1662 write_sequnlock(&jiffies_lock
);